This invention is concerned with a flexible protective sleeve for use in protecting an elongated member, such as a wire, a bundle of wires, or a pipe. Such sleeves, conventionally, comprise a generally tubular wall for at least substantially surrounding the member.
Conventionally, flexible protective sleeves are used for protecting wires or pipes from contact with other components to avoid undesirable noise generation and/or abrasion damage. Such sleeves may also act to insulate a member from heat and may have a metallic layer deposited thereon or adhered thereto in order to reflect away infra-red radiation. Such sleeves are used, for example, in the engine compartments of vehicles. Some flexible protective sleeves have a longitudinal slit in their wall to enable an elongated member to be positioned in the sleeve.
This invention is applicable, for example, to flexible protective sleeves of the convoluted type. Such a sleeve has its wall formed from sheet plastics material which is formed into convolutions to increase flexibility, ie the wall has a diameter which varies in a regular manner along the length of the sleeve so that the exterior surface has a series of annular crests separated by troughs. When the sleeve bends, the crests move further apart on the outside of the curve and closer together on the inside of the curve.
Although flexible protective sleeves of the convoluted type are effective in protecting elongated members contained therein from abrasion damage and, in many cases, reduce noise, the sleeves themselves can also be a source of noise, since they may vibrate against the elongated member causing an undesirable rattle. Various proposals have been made for reducing this rattling noise. For example, the problem of reducing noise from such sleeves has been considered in EP 0 556 140 B where the proposed solution is to cover the wall of the sleeve with a strip of sound-insulating material, eg felt, which is adhered to the wall of the sleeve. The strip covers the outer surface of the wall and passes through a slit to cover the inner surface of the wall. Thus, the strip can cushion impacts both between the exterior surface of the wall and adjacent components and also impacts between the interior surface of the wall and the elongated member. However, the use of such a strip has the disadvantages that: the process of applying the strip is complex; the strip may absorb liquids; the bulk of the sleeve is considerably increased; and the strip may become detached in service.
It is an object of the present invention to provide a flexible protective sleeve in which the problem of rattling mentioned-above is reduced or eliminated without incurring the above-mentioned disadvantages.
The invention provides a flexible protective sleeve for use in protecting an elongated member, the sleeve comprising a generally tubular wall for at least substantially surrounding the member, characterized in that the sleeve also comprises permanent adhesive adhered to an interior surface of said wall, said adhesive being effective to stick the elongated member to said interior surface of the wall.
The term xe2x80x9cpermanent adhesivexe2x80x9d is used herein to denote an adhesive which remains sticky orxe2x80x9ctackyxe2x80x9d for long periods so that it can hold an elongated member on contact and, if said member becomes detached, the adhesive can re-establish adhesion on further contact. Such adhesives are well-known and find applications, eg in holding posters on walls, in self-adhesive tapes, etc. One suitable permanent adhesive is a surfactant stabilized acrylic ester copolymer dispersed in water marketed by Harlow Chemical Company under the designation xe2x80x9cRevacryl 398xe2x80x9d. This dispersion can be sprayed on to a surface and dries to form a film of high cohesive strength with moderate tack and adhesion to the surface.
In a protective sleeve according to the invention, when the elongated member contacts the interior surface of the wall of the sleeve, said adhesive sticks the member to the sleeve preventing relative movement therebetween and hence preventing rattling. Should the adhesion be broken at any point, it can be re-established at the same or a different point upon further contact.
The invention is applicable to protective sleeves in which the wall is formed from sheet plastics material and is convoluted but is also applicable to sleeves formed in other ways, eg by braiding or weaving monofilaments or yarns.
It is not necessary for the permanent adhesive to entirely cover the interior surface of the wall of the sleeve. Indeed, in the case of a convoluted sleeve, only adhesive on the crests of the interior surface will be effective. For example, the adhesive can cover discrete areas of said interior surface, eg as bands of adhesive following a helical path along the sleeve, or asxe2x80x9cislandsxe2x80x9d of adhesive distributed in a pattern, or only on the crests.
Where a sleeve according to the invention has a longitudinal slit to allow insertion of the elongated member, the adhesive can be applied as a spray, preferably water-based, from a nozzle inserted through the slit while the sleeve is moved past the nozzle. It is possible also to provide that the slit has overlapping edge regions to one of which the adhesive is applied so that the adhesive can be used to seal the slit.